<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>complement</title>
</head>

<body>
    <div>打开浏览器控制台查看结果</div>
    <script>
        const complement =
            handler =>
                (...args) =>
                    !fn(...args);
        const isEven = num => num % 2 === 0;
        const isOdd = complement(isEven);
        console.log(isOdd(2)); // false
        console.log(isOdd(3)); // true
    </script>
</body>

</html>